Typically photographic sheet film, utilized for professional commercial photography, is packaged in a protective four-sided hermetically sealed pouch, and the pouch placed in a two or three-part "set-up" box constructed of corrugated, kraft, or chipboard materials. The pouch is generally constructed of an outer layer of paper, a second layer of polyethylene or adhesive, a third layer of aluminum foil, a fourth layer of polyethylene or adhesive, and a fifth layer of polyethylene, this last layer sometimes containing carbon black for additional light-shielding properties. Generally, the pouch structure has minimal oxygen barrier properties and minimal puncture resistance. The paper component typically comprises the bulk of the structure. Since paper has limited strength, it is prone to pin holing and tearing during both the loading of the sheet film into the bag and the loading of the bag into the box. Generally there are either ten or twenty five sheets of square-cut film in a stack, and a paper card (square-cut to the approximate size of the film) on both the top and bottom of the stack. The sharp corners of the film and the cards can slice the laminate material during the packaging operation, and especially during the rigors of the transportation cycle. The tears/pin holes are generally created where the corners of the stack interface with the pouch. Thus a breach of the hermetically sealed pouch is often created. Moisture and dirt can potentially enter these small openings and damage the sensitive film. Such damage may not be discovered until the photographer has taken and developed his pictures. Moreover, damage in the form of abrasions to the emulsion of the film may occur during transport. This latter damage is not related to moisture or dirt but to the individual sheets of film in the stack rubbing against each other during periods of package vibration and shock associated with shipping over long distances. One way to alleviate this problem is to evacuate air out of the pouch prior to the sealing operation. If this evacuation can be maintained during transport, the film stack is effectively immobilized, thereby preventing such abrasion. Experience indicates that an optimal level of air evacuation is required, above which damage will result to the sensitive film emulsion and below which the film will not be secured and immobilized in the pouch. Therefore, conventional pouch materials, made of mostly paper, are not well suited for solving the above problem because of their ability to develop pin holes and tears. Thus, a need exists for a stronger pouch material to ensure product protection during shipping and handling.
A further problem with conventional pouches for photographic sheet film is that the pouch is not reusable. Photographers, on location, often store exposed and unused film inside of the box and discard the opened pouch. Since the user generally physically tears the pouch open it is typically partially destroyed, preventing effective reuse. Storing the film directly in the box only can lead to dirt and moisture contamination of the film. However, if the pouch material were opened in a non-destructive manner and were of sufficient length to fold over one end of the pouch as a flap, the pouch would likely be retained for reuse. Moreover, the film would be more likely to be placed back into the pouch before being inserted in the box. One solution to this reusability problem is to offer extra, unused pouches in the box specifically for this purpose. However, a major shortcoming of this solution is that it adds significant cost and results in additional packaging materials for the solid waste stream. Therefore, a need persists for a stronger pouch material which can be opened easily and in a non-destructive manner to allow package reuse, which is a value-added feature for the photographer.
Yet another problem with conventional pouches for photographic sheet film is the inability to load the sealed, partially-evacuated pouch into the two or three-part set-up box, and to keep the pouch from pushing open the box. The box is generally sized close to the film size, for a tight fit to help minimize product movement/damage during shipping and to minimize packaging material costs. The current paper-based materials exhibit "dead fold" characteristics, i.e., they exhibit memory, such that when folded they tend to retain the fold. The pouch is typically over-sized, to facilitate the loading of the film into the pouch. Therefore the "flaps" of the four-sided sealed pouch must be folded for loading into the box. Given the "dead fold" characteristics of the current materials the pouch tends to load easily and lay down flat in the box tray. Materials with adequate strength to resist tearing tend to be of such stiffness and caliper that when the four-sided pouch is loaded into the box, the four folded flaps resist staying down in the box tray. The pouch tends to protrude above the tray. This can interfere with the assembly of the remaining box part(s), and with the subsequent labeling operation (a label is typically wrapped around the three panels of the box for product identification and to help ensure that the box remains closed). If the pouch is dramatically oversized, such that the four flaps are longer, the flaps tend to stay folded under the pouch better, but the excess material is undesirable from a cost and an environmental standpoint. Also pouch reuse is extremely difficult, as there is so much excess, stiff pouch material to fold and fit into the tight box. The packaging operation is typically manual but this problem would be inherent in either a manual or an automated packaging operation with a stronger pouch material.
Several attempts in various fields of endeavor have been made to address some of the above problems. U.S. Pat. No. 2,189,174 by Hohl teaches a pouch style allowing non-destructive opening, for the dispensing of "flowable" products such as coffee and sugar. Pleats are formed in the pouch, and these pleats act as finger tabs, which the user can grasp to separate the two pouch panels at the seam. Shortcomings of this pouch for solving the problems faced by applicant are that it does not allow for ease of film sheet loading and lacks puncture resistance.
U.S. Pat. No. 4,377,862 by Suter teaches a peel open h-wrap style pouch for vertical form-fill-seal applications, where the package is made in-line, just prior to product filling. The Suter pouch utilizes a paper web which is treated with a composition and coated with an adhesive.
U.S. Pat. No. 4,964,515 by Heyden teaches an easy-open h-wrap style pouch, with a tubular pocket in the seal area for the user to insert a finger. The finger is slid along the remainder of the seal to separate the two layers of pouch material. Shortcomings of this pouch for solving the problems faced by applicant are that it does not allow for ease of film sheet loading, ease of opening and it lacks puncture resistance.
Finally, U.S. Pat. No. 4,705,174 by Goglio teaches a peel open h-wrap style gusseted pouch utilizing a puncture-resistant material. The Goglio invention utilizes a defined strip of peel material, placed adjacent to the pouch opening, and the peel material is a blend of polyethylene and an ionomer.
Therefore, a need persists for a stronger packaging material for sheet film pouches which would eliminate tearing/pinholing. Moreover, there exists a need for a cost efficient, easy opening pouch that would facilitate film sheet loading with both manual and automatic packaging equipment, and would allow an unsealed box to remain closed.